DUDE!! this is the first time ever i have heard any girl gifting a guy something related to his car.
My girlfriend will gift me everything else other than the car accessories.
Salute to your GF. may be she can conduct some seminars and classes to tell other gals what men really want
congrats on your Sub and Amp, belated birthday!!
there are lots of good installers in mumbai. else you can go to the same place where she got it fitted from and supervise the stuffs yourself. get the amp out of the seats and place it in boot which will be free from dust. also get the wiring done properly. he will do it for free if you have purchased the sub and amp from him.